Several researchers have shown that perinatal nutritional deficiencies alter appetitive motivation. These persistent motivational differences confound the interpretation of research designed to examine the relationship between nutritional deficit and learning. While some investigators have utilized electric shock specifically to avoid the problems of appetitive motivation, there is evidence which suggests that aversion thresholds may also be altered by perinatal nutritional deficiencies. As electric shock serves as a precise and convenient form of motivation in this type of research, the relationship between aversion thresholds and nutritional deficit is critical to the interpretation of learning and memory effects. This proposal outlines a systematic investigation of aversion thresholds in rats which had experienced nutritional deficiencies during gestation and/or lactation. A spatial preference technique will be employed with a l50K ohm fixed impedance AC shock source. These data will then be augmented by data from an alleyway shock escape task. With this information, learning and memory studies can be designed to avoid the confounding of motivational differences.